期刊文献+
共找到1,066篇文章
< 1 2 54 >
每页显示 20 50 100
Research on the Method of Heat Preservation and Heating for the Drilling System of Polar Offshore Drilling Platform
1
作者 Yingkai Dong Chaohe Chen +2 位作者 Guangyan Jia Lidai Wang Jian Bai 《Energy Engineering》 EI 2024年第5期1173-1193,共21页
This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig system.Combining the basic theory of heat transfer with the environmental requ... This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig system.Combining the basic theory of heat transfer with the environmental requirements of polar drilling operations and the characteristics of polar drilling processes,we analyze the factors that affect the insulation effect of the drilling rig system.These factors include the thermal conductivity of the insulation material,the thickness of the insulation layer,ambient temperature,and wind speed.We optimize the thermal insulation material of the polar drilling rig system using a steady-state method to measure solid thermal conductivity.By analyzing the distribution of temperature in space after heating,we optimize the distribution and air outlet angle of the heater using Fluent hydrodynamics software.The results demonstrate that under polar conditions,polyisocyanurate with stable thermodynamic properties is selected as the thermal insulation material.The selection of thermal insulation material and thickness significantly affects the thermal insulation effect of the system but has little effect on its heating effect.Moreover,when the air outlet angle of the heater is set to 32.5°,the heating efficiency of the system can be effectively improved.According to heat transfer equations and heat balance theory,we determine that the heating power required for the system to reach 5°C is close to numerical simulation. 展开更多
关键词 Polar drilling drilling system fluid dynamics heat preservation and heating numerical simulation
下载PDF
Apatite Fission Track Thermochronology of Granite from the Xiazhuang Uranium Ore Field,South China:Implications for Exhumation History and Ore Preservation
2
作者 SUN Yue CHEN Zhengle +4 位作者 PAN Jiayong HUO Hailong LI Haidong SUN Junjie XU Guangchun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期430-440,共11页
Xiazhuang uranium ore field,located in the southern part of the Nanling Metallogenic Belt,is considered one of the largest granite-related U regions in South China.In this paper,we contribute new apatite fission track... Xiazhuang uranium ore field,located in the southern part of the Nanling Metallogenic Belt,is considered one of the largest granite-related U regions in South China.In this paper,we contribute new apatite fission track data and thermal history modeling to constrain the exhumation history and evaluate preservation potential of the Xiazhuang Uranium ore field.Nine Triassic outcrop granite samples collected from different locations of Xiazhuang Uranium ore field yield AFT ages ranging from 43 to 24 Ma with similar mean confined fission track lengths ranging from 11.8±2.0 to 12.9±1.9μm and Dpar values between 1.01 and 1.51μm.The robustness time-temperature reconstructions of samples from the hanging wall of Huangpi fault show that the Xiazhuang Uranium ore field experienced a time of monotonous and slow cooling starting from middle Paleocene to middle Miocene(~60-10 Ma),followed by relatively rapid exhumation in the late Miocene(~10-5 Ma)and nearly thermal stability in the Pliocene-Quaternary(~5-0 Ma).The amount of exhumation after U mineralization since the Middle Paleogene was estimated as~4.3±1.8 km according to the integrated thermal history model.Previous studies indicate that the ore-forming ages of U deposits in the Xiazhuang ore field are mainly before Middle Paleocene and the mineralization depths are more than 4.4±1.2 km.Therefore,the exhumation history since middle Paleocene plays important roles in the preservation of the Xiazhuang Uranium ore field. 展开更多
关键词 apatite fission track exhumation history ore preservation Xiazhuang Uranium ore field South China
下载PDF
Trusted Certified Auditor Using Cryptography for Secure Data Outsourcing and Privacy Preservation in Fog-Enabled VANETs
3
作者 Nagaraju Pacharla K.Srinivasa Reddy 《Computers, Materials & Continua》 SCIE EI 2024年第5期3089-3110,共22页
With the recent technological developments,massive vehicular ad hoc networks(VANETs)have been established,enabling numerous vehicles and their respective Road Side Unit(RSU)components to communicate with oneanother.Th... With the recent technological developments,massive vehicular ad hoc networks(VANETs)have been established,enabling numerous vehicles and their respective Road Side Unit(RSU)components to communicate with oneanother.The best way to enhance traffic flow for vehicles and traffic management departments is to share thedata they receive.There needs to be more protection for the VANET systems.An effective and safe methodof outsourcing is suggested,which reduces computation costs by achieving data security using a homomorphicmapping based on the conjugate operation of matrices.This research proposes a VANET-based data outsourcingsystem to fix the issues.To keep data outsourcing secure,the suggested model takes cryptography models intoaccount.Fog will keep the generated keys for the purpose of vehicle authentication.For controlling and overseeingthe outsourced data while preserving privacy,the suggested approach considers the Trusted Certified Auditor(TCA).Using the secret key,TCA can identify the genuine identity of VANETs when harmful messages aredetected.The proposed model develops a TCA-based unique static vehicle labeling system using cryptography(TCA-USVLC)for secure data outsourcing and privacy preservation in VANETs.The proposed model calculatesthe trust of vehicles in 16 ms for an average of 180 vehicles and achieves 98.6%accuracy for data encryption toprovide security.The proposedmodel achieved 98.5%accuracy in data outsourcing and 98.6%accuracy in privacypreservation in fog-enabled VANETs.Elliptical curve cryptography models can be applied in the future for betterencryption and decryption rates with lightweight cryptography operations. 展开更多
关键词 Vehicular ad-hoc networks data outsourcing privacy preservation CRYPTOGRAPHY keys trusted certified auditors data security
下载PDF
Pharmacological methods for ovarian function and fertility preservation in women with cancer:A literature review
4
作者 ANA S.CVETANOVIC MATTEO LAMBERTINI +5 位作者 KEVIN PUNIE GORANA G.MATOVINA BRKO NIKOLA D.ZIVKOVIC MAJA J.POPOVIC MARIJANA M.MILOVIC KOVACEVIC LAZAR S.POPOVIC 《Oncology Research》 SCIE 2024年第8期1309-1322,共14页
Oncofertility is an extremely significant topic that is increasingly being discussed owing to increased evidence indicating that fertility preservation does not affect the treatment outcomes of patients with cancer but... Oncofertility is an extremely significant topic that is increasingly being discussed owing to increased evidence indicating that fertility preservation does not affect the treatment outcomes of patients with cancer but significantly contributes to preserving life quality.The effect of chemotherapy can range from minimal effects to complete ovarian atrophy.Limited data are available on the effects of monoclonal antibodies and targeted therapies on the ovaries and fertility.Temporary ovarian suppression by administering a gonadotropin-releasing hormone agonist(GnRHa)during chemotherapy decreases the gonadotoxic effect of chemotherapy,thereby diminishing the chance of developing premature ovarian insufficiency(POI).At present,the concomitant administration of GnRH analogs during chemotherapy is the only accepted pharmacological method for preserving ovarian function.Notably,most randomized studies on the effectiveness of luteinizing hormone-releasing hormone agonists during chemotherapy in preventing POI have been conducted in women with breast cancer,with a considerably small number of studies on patients with hematological malignancies.Furthermore,most randomized controlled trials on breast cancer have revealed a decrease in treatment-induced POI risk,regardless of the hormone receptor status.In addition,studies on hematological malignancies have yielded negative results;nevertheless,thefindings must be interpreted with caution owing to numerous limitations.Current guidelines from the American Society of Clinical Oncology and ESMO Clinical Practice Guidelines recommend sperm,oocyte,and embryo cryopreservation as a standard practice and only offering GnRHa to patients when proven fertility preservation methods are not feasible.In this manuscript,we present a comprehensive literature overview on the application of ovarian suppression with GnRHa during chemotherapy in patients with cancer by addressing preclinical and clinical data,as well as future perspectives in thisfield that upcoming research should focus on. 展开更多
关键词 Gonadotropin-releasing hormone agonists(GnRHa) Fertility preservation Premature ovarian insufficiency(POI) Premenopausal patients
下载PDF
Exploring the combination of biochar‐amended soil and automated irrigation technology for water regulation and preservation in green infrastructure
5
作者 Honghu Zhu Yuanxu Huang +4 位作者 Haihong Song Jian Chen Songlei Han Tanwee Mazumder Ankit Garg 《Deep Underground Science and Engineering》 2024年第1期39-52,共14页
Biochar is a carbon sink material with the potential to improve water retention in various soils.However,for the long‐term maintenance of green infrastructure,there is an additional need to regulate the water content... Biochar is a carbon sink material with the potential to improve water retention in various soils.However,for the long‐term maintenance of green infrastructure,there is an additional need to regulate the water contents in the covers to maintain vegetation growth in semiarid conditions.In this study,biochar‐amended soil was combined with subsurface drip irrigation,and the water preservation characteristics of this treatment were investigated through a series of one‐dimensional soil column tests.To ascertain the best treatment method specific to semiarid climatic conditions,the test soil was amended with 0%,1%,3%,and 5%biochar.Automatic irrigation devices equipped with soil moisture sensors were used to control the subsurface water content with the aim of enhancing vegetation growth.Each soil column test lasted 150 h,during which the volumetric water contents and soil suction data were recorded.The experimental results reveal that the soil specimen amended with 3%biochar is the most water‐saving regardless of the time cost.Soil with a higher biochar content(e.g.,5%)consumes a more significant amount of water due to the enhancement of the water‐holding capacity.Based on the experimental results,it can be concluded that the appropriate ratio can be determined within 1%–3%,which can reduce not only the amount of irrigated/used water but also the time cost.Such technology can be explored for water content regulation in green infrastructure and the development of barriers for protecting the environment around deep underground waste containment. 展开更多
关键词 BIOCHAR drip irrigation UNDERGROUND water preservation water regulation
下载PDF
Implementation of a New Solution for the Preservation of Anatomical Specimens Made of Non-Toxic Substances
6
作者 Ma Reyes Pichardo-Molinero Samantha Jardon-Xicotencatl +1 位作者 Misael R. Oliver-González Carlos G. García-Tovar 《Open Journal of Veterinary Medicine》 CAS 2024年第3期56-67,共12页
The preservation of anatomical pieces in Veterinary Anatomy is essential since it is not possible to dissect all domestic species. Most techniques use reagents with high levels of toxicity such as formaldehyde. The ob... The preservation of anatomical pieces in Veterinary Anatomy is essential since it is not possible to dissect all domestic species. Most techniques use reagents with high levels of toxicity such as formaldehyde. The objective of this work was to develop a new preservation technique that uses reagents with zero toxicity and that allows obtaining preserved pieces suitable for anatomical studies. The alcohol propylene glycol technique was developed, the method of which uses a fixation step with alcohol, sodium chloride, commercial vinegar and subsequently the impregnation of the preservation solution made from propylene glycol and commercial vinegar, which are non-toxic. As a result of this work, adequately preserved sheep hearts were obtained that preserved their morphology with slight changes in size and weight, which did not affect their external and internal anatomical structure. Its coloration was not substantially affected, remaining a little lighter. The pieces obtained showed flexibility which allowed dissections to be carried out. The time to develop the technique was 20 days. A comparative study was carried out with the phenolated glycerin technique that uses toxic reagents (formaldehyde and phenol) and the pieces obtained with the alcohol propylene glycol technique were of better quality, observing that the pieces with phenolated glycerin tend to darken and are more rigid. And the time to develop the technique is 24 days. In conclusion, a preservation technique for anatomical pieces was developed that allowed the preservation of the organs under study, which allow their use for anatomical studies, and which have been preserved without changes until the time of this publication (8 months) and there are pieces preserved with this technique for 2 years. 展开更多
关键词 Veterinary Anatomy Heart preservation Techniques Alcohol Propylene Glycol Technique FIXATION NECROPSY Toxic Chemicals
下载PDF
Organ and function preservation in gastrointestinal cancer: Current and future perspectives on endoscopic ablation
7
作者 Youssef Yousry Soliman Megan Soliman +2 位作者 Shravani Reddy James Lin Toufic Kachaamy 《World Journal of Gastrointestinal Endoscopy》 2024年第6期282-291,共10页
The escalating prevalence of gastrointestinal cancers underscores the urgency for transformative approaches.Current treatment costs amount to billions of dollars annually,combined with the risks and comorbidities asso... The escalating prevalence of gastrointestinal cancers underscores the urgency for transformative approaches.Current treatment costs amount to billions of dollars annually,combined with the risks and comorbidities associated with invasive surgery.This highlights the importance of less invasive alternatives with organ preservation being a central aspect of the treatment paradigm.The current standard of care typically involves neoadjuvant systemic therapy followed by surgical resection.There is a growing interest in organ preservation approaches by way of minimizing extensive surgical resections.Endoscopic ablation has proven to be useful in precursor lesions,as well as in palliative cases of unrese-ctable disease.More recently,there has been an increase in reports on the utility of adjunct endoscopic ablative techniques for downstaging disease as well as contributing to non-surgical complete clinical response.This expansive field within endoscopic oncology holds great potential for advancing patient care.By addressing challenges,fostering collaboration,and embracing technological advancements,the gastrointestinal cancer treatment paradigm can shift towards a more sustainable and patient-centric future emphasizing organ and function preservation.This editorial examines the evolving landscape of endoscopic ablation strategies,emphasizing their potential to improve patient outcomes.We briefly review current applications of endoscopic ablation in the esophagus,stomach,duodenum,pancreas,bile ducts,and colon. 展开更多
关键词 Gastrointestinal cancer Endoscopic ablation Organ preservation Complete clinical response Neoadjuvant therapy Endoscopic oncology Palliative treatment
下载PDF
Extracellular Vesicles from Mesenchymal Stromal Cells (imEVs) Improve Cold Preservation of Isolated Mitochondria
8
作者 Xianpeng Jiang Sergey Rodin +3 位作者 Ken Braesch-Andersen Catherine C. Baucom Karl-Henrik Grinnemo Brent Segal 《Journal of Biosciences and Medicines》 2024年第1期52-63,共12页
Mitochondrial organelle transplantation (MOT) is an innovative strategy for the treatment of mitochondrial dysfunction such as cardiac ischemic reperfusion injuries, Parkinson’s diseases, brain and spinal cord injuri... Mitochondrial organelle transplantation (MOT) is an innovative strategy for the treatment of mitochondrial dysfunction such as cardiac ischemic reperfusion injuries, Parkinson’s diseases, brain and spinal cord injuries, and amyotrophic lateral sclerosis (ALS). However, one of the major challenges for widespread usage is a methodology for preservation of isolated mitochondria. Extracellular vesicles (EVs) are phospholipid bilayer-enclosed vesicles released from cells. EVs carry a cargo of proteins, nucleic acids, lipids, metabolites, and even organelles such as mitochondria. Purpose: To test if EVs enhance the stability of isolated mitochondria. Methods: We mixed isolated mitochondria of fibroblasts with EVs of mesenchymal stromal cells (imEVs) (9:1 in volume) and stored the mixture at 2°C - 6°C for different time periods. We measured morphology, mitochondrial membrane potential (MMP) and mitochondrial ATP content at 0, 2, 5 days. Key findings: After 2 days of storage, the mito-chondria without imEVs lost approximate 70% MMP (RFU: 1822 ± 68), compared to the fresh mitochondria (RFU: 5458 ± 52) (p 0.05). In agreement with MMP, mitochondria without imEVs lost significant mitochondrial ATP content (p 0.05), after 2 days of cold storage, compared to fresh mitochondria. Microscopy showed that imEVs promoted aggregation of isolated mitochondria. Summary: The preliminary data showed that imEVs enhanced the stability of isolated mitochondria in cold storage. 展开更多
关键词 MITOCHONDRIA Extracellular Vesicles Mitochondrial preservation MOT imEVs
下载PDF
Analysis of the Application Effect and Value of Dydrogesterone in The Treatment of Preeclampsia for Fetal Preservation
9
作者 Dongmei Shen 《Journal of Clinical and Nursing Research》 2024年第4期143-148,共6页
Objective: To analyze the application effect and value of dydrogesterone in the fertility preservation treatment of preeclampsia. Methods: Forty cases of patients with preeclampsia admitted to our hospital between Jan... Objective: To analyze the application effect and value of dydrogesterone in the fertility preservation treatment of preeclampsia. Methods: Forty cases of patients with preeclampsia admitted to our hospital between January 2023 and January 2024 were divided randomly into a control group and an observation group of 20 cases each. The control group applied progesterone to preserve the fetus, and the observation group applied dydrogesterone. The symptom relief time, hormone levels before and after treatment, as well as adverse drug reactions, and the effect of fetal preservation between the two groups were compared. Results: The time to relieve vaginal bleeding, abdominal pain. and lumbago in the observation group was shorter than that in the control group (P < 0.05). After treatment, the progesterone levels and incidence of adverse drug reactions in the observation group were lower than those in the control group (P < 0.05). The success rate of fertility preservation in the observation group was higher than that in the control group (P < 0.05). Conclusion: In the treatment of fetal preservation of preeclampsia, the application of dydrogesterone positively alleviated vaginal bleeding, abdominal pain, and lumbago, with mild adverse reactions and a good effect on fetal preservation. 展开更多
关键词 PREECLAMPSIA Fertility preservation treatment DYDROGESTERONE Application effect
下载PDF
Research on the Development Strategy of Panxi Sunshine Health and Wellness Homestays and Hotels Based on Traditional Chinese Medicine Health Preservation
10
作者 Zihui Zhao Zhengnan Wuyu +1 位作者 Sicen Liu Chuibiao Zeng 《Proceedings of Business and Economic Studies》 2024年第3期114-119,共6页
This study is the first phase of research results from the student innovation project“Yunqiao Sunshine Health and Wellness Homestay”group at Chengdu Normal University.By analyzing the current state of the Sunshine H... This study is the first phase of research results from the student innovation project“Yunqiao Sunshine Health and Wellness Homestay”group at Chengdu Normal University.By analyzing the current state of the Sunshine Health and Wellness Tourism Area economy in the Panxi region of Sichuan,local policies,and the current state of Sunshine Health and Wellness homestays and hotels,this paper proposes the possibility of developing Sunshine Health and Wellness homestays and hotels through traditional Chinese medicine(TCM)health preservation methods.It also proposes development strategies for such hotels through a market survey SWOT analysis. 展开更多
关键词 Traditional Chinese medicine health preservation Sunshine Health and Wellness Tourism Area Homestays and hotels STRATEGY
下载PDF
Minimally invasive spleen-preserving distal pancreatectomy: Does splenic vessel preservation have better postoperative outcomes? A systematic review and meta-analysis 被引量:3
11
作者 Fady Elabbasy Rahul Gadde +3 位作者 Mena M Hanna Danny Sleeman Alan Livingstone Danny Yakoub 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2015年第4期346-353,共8页
BACKGROUND: Minimally invasive spleen-preserving distal pancreatectomy (SPDP) can be performed with either splenic vessel preservation (SVP) or resection [Warshaw procedure (WP)]. The aim of this study was to e... BACKGROUND: Minimally invasive spleen-preserving distal pancreatectomy (SPDP) can be performed with either splenic vessel preservation (SVP) or resection [Warshaw procedure (WP)]. The aim of this study was to evaluate the postoperative clinical outcomes of patients undergoing both methods. DATA SOURCES: Database search of PubMed, Embase, Scopus, Cochrane, and Google Scholar was performed (2000-2014); key bibliographies were reviewed. Qualified studies compar- ing patients undergoing SPDP with either SVP or WP, and as- sessing postoperative complications were included. Calculated pooled risk ratio (RR) with the corresponding 95% confidence interval (CI) by random effects methods were used in the meta-analyses. RESULTS: The search yielded 215 studies, of which only 14 observational studies met our selection criteria. The studies included 943 patients in total; 652 (69%) underwent SVP and 291 (31%) underwent WP. Overall, there was a lower incidence of splenic infarction (RR=0.17; 95% Ch 0.09-0.33; P〈0.001), gastric varices (RR=0.16; 95% Ch 0.05-0.51; P=0.002), and intra/postoperative splenectomy (RR=0.20; 95% Ch 0.08-0.49; P〈0.001) in the SVP group. There was no difference in in- cidence of pancreatic fistula (WP vs SVP, 23.6% vs 22.9%;P=0.37), length of hospital stay, operative time or blood loss. There was moderate cross-study heterogeneity. CONCLUSIONS: SVP is a safe, efficient and feasible technique that may be used to preserve the spleen. WP may be more suit- able for large tumors dose to the splenic hilum or those associ- ated with splenomegaly. Randomized clinical trials are justified to examine the long-term benefits of SVP-SPDP. 展开更多
关键词 splenic infarction spleen-preserving distal pancreatectomy splenic vessel preservation Warshaw procedure gastric varices
下载PDF
Property Preservation of Petri Synthesis Net Based Representation for Embedded Systems 被引量:2
12
作者 Chuanliang Xia Chengdong Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第4期905-915,共11页
Embedded systems have numerous applications in everyday life.Petri-net-based representation for embedded systems(PRES+)is an important methodology for the modeling and analysis of these embedded systems.For a large co... Embedded systems have numerous applications in everyday life.Petri-net-based representation for embedded systems(PRES+)is an important methodology for the modeling and analysis of these embedded systems.For a large complex embedded system,the state space explosion is a difficult problem for PRES+to model and analyze.The Petri net synthesis method allows one to bypass the state space explosion issue.To solve this problem,as well as model and analyze large complex systems,two synthesis methods for PRES+are presented in this paper.First,the property preservation of the synthesis shared transition set method is investigated.The property preservation of the synthesis shared transition subnet set method is then studied.An abstraction-synthesis-refinement representation method is proposed.Through this representation method,the synthesis shared transition set approach is used to investigate the property preservation of the synthesis shared transition subnet set operation.Under certain conditions,several important properties of these synthetic nets are preserved,namely reachability,timing,functionality,and liveness.An embedded control system model is used as an example to illustrate the effectiveness of these synthesis methods for PRES+. 展开更多
关键词 Modeling Petri nets property preservation SUBNET SYNTHESIS
下载PDF
Evaluation of the oil and gas preservation conditions, source rocks, and hydrocarbongenerating potential of the Qiangtang Basin: New evidence from the scientific drilling project 被引量:2
13
作者 Li-jun Shen Jian-yong Zhang +4 位作者 Shao-yun Xiong Jian Wang Xiu-gen Fu Bo Zheng Zhong-wei Wang 《China Geology》 CAS CSCD 2023年第2期187-207,共21页
The Qiangtang Basin of the Tibetan Plateau,located in the eastern Tethys tectonic domain,is the largest new marine petroliferous region for exploration in China.The scientific drilling project consisting primarily of ... The Qiangtang Basin of the Tibetan Plateau,located in the eastern Tethys tectonic domain,is the largest new marine petroliferous region for exploration in China.The scientific drilling project consisting primarily of well QK-1 and its supporting shallow boreholes for geological surveys(also referred to as the Project)completed in recent years contributes to a series of new discoveries and insights into the oil and gas preservation conditions and source rock evaluation of the Qiangtang Basin.These findings differ from previous views that the Qiangtang Basin has poor oil and gas preservation conditions and lacks high-quality source rocks.As revealed by well QK-1 and its supporting shallow boreholes in the Project,the Qiangtang Basin hosts two sets of high-quality regional seals,namely an anhydrite layer in the Quemo Co Formation and the gypsum-bearing mudstones in the Xiali Formation.Moreover,the Qiangtang Basin has favorable oil and gas preservation conditions,as verified by the comprehensive study of the sealing capacity of seals,basin structure,tectonic uplift,magmatic activity,and groundwater motion.Furthermore,the shallow boreholes have also revealed that the Qiangtang Basin has high-quality hydrocarbon source rocks in the Upper Triassic Bagong Formation,which are thick and widely distributed according to the geological and geophysical data.In addition,the petroleum geological conditions,such as the type,abundance,and thermal evolution of organic matter,indicate that the Qiangtang Basin has great hydrocarbon-generating potential. 展开更多
关键词 Scientific drilling project Oil and gas preservation Source rock Quemo Co Formation Oil and gas exploration engineering Qiangtang Basin Tibet
下载PDF
Enhanced Clustering Based OSN Privacy Preservation to Ensure k-Anonymity, t-Closeness, l-Diversity, and Balanced Privacy Utility 被引量:1
14
作者 Rupali Gangarde Amit Sharma Ambika Pawar 《Computers, Materials & Continua》 SCIE EI 2023年第4期2171-2190,共20页
Online Social Networks (OSN) sites allow end-users to share agreat deal of information, which may also contain sensitive information,that may be subject to commercial or non-commercial privacy attacks. Asa result, gua... Online Social Networks (OSN) sites allow end-users to share agreat deal of information, which may also contain sensitive information,that may be subject to commercial or non-commercial privacy attacks. Asa result, guaranteeing various levels of privacy is critical while publishingdata by OSNs. The clustering-based solutions proved an effective mechanismto achieve the privacy notions in OSNs. But fixed clustering limits theperformance and scalability. Data utility degrades with increased privacy,so balancing the privacy utility trade-off is an open research issue. Theresearch has proposed a novel privacy preservation model using the enhancedclustering mechanism to overcome this issue. The proposed model includesphases like pre-processing, enhanced clustering, and ensuring privacy preservation.The enhanced clustering algorithm is the second phase where authorsmodified the existing fixed k-means clustering using the threshold approach.The threshold value is determined based on the supplied OSN data of edges,nodes, and user attributes. Clusters are k-anonymized with multiple graphproperties by a novel one-pass algorithm. After achieving the k-anonymityof clusters, optimization was performed to achieve all privacy models, suchas k-anonymity, t-closeness, and l-diversity. The proposed privacy frameworkachieves privacy of all three network components, i.e., link, node, and userattributes, with improved utility. The authors compare the proposed techniqueto underlying methods using OSN Yelp and Facebook datasets. The proposedapproach outperformed the underlying state of art methods for Degree ofAnonymization, computational efficiency, and information loss. 展开更多
关键词 Enhanced clustering online social network K-ANONYMITY t-closeness l-diversity privacy preservation
下载PDF
Preservation of Raw Camel Milk by Lactoperoxidase System Using Hydrogen Peroxide Producing Lactic Acid Bacteria
15
作者 Dakalo Dashe Egon Bech Hansen +5 位作者 Mohammed Yusuf Kurtu Tesfemariam Berhe Mitiku Eshetu Yonas Hailu Amsalu Waktola Adane Shegaw 《Open Journal of Animal Sciences》 2020年第3期387-401,共15页
This study was conducted to investigate the effect of lactic acid bacteria (LAB) activated lactoperoxidase system (LPs) on keeping quality of raw camel milk at room temperature. Camel milk samples were collected from ... This study was conducted to investigate the effect of lactic acid bacteria (LAB) activated lactoperoxidase system (LPs) on keeping quality of raw camel milk at room temperature. Camel milk samples were collected from Errer valley, Babile district of eastern Ethiopia. The level of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) for activation of LPs was optimized using different levels of exogenous H<sub>2</sub>O<sub>2</sub>. Strains of LAB (<span style="white-space:nowrap;"><i></span>Lactococcus lactis 22333<span style="white-space:nowrap;"></i></span>, <span style="white-space:nowrap;"><i></span>Weissella confusa<span style="white-space:nowrap;"></i></span> 22308, <span style="white-space:nowrap;"><i></span>W. confusa<span style="white-space:nowrap;"></i></span> 22282, <span style="white-space:nowrap;"><i></span>W. confusa<span style="white-space:nowrap;"></i></span> 22296, <span style="white-space:nowrap;"><i></span>S. Infatarius<span style="white-space:nowrap;"></i></span> 22279 and <span style="white-space:nowrap;"><i></span>S. lutetiensis<span style="white-space:nowrap;"></i></span> 22319) with H<sub>2</sub>O<sub>2</sub> producing properties were evaluated, and <i>W. confusa</i> 22282 was selected as the best strain to produce H<sub>2</sub>O<sub>2</sub>. Storage stability of the milk samples was evaluated through the acidification curves, titratable acidity (TA), total bacterial count (TBC) and coliform counts (CC) at storage times of 0, 6, 12, 18, 24 and 48 hours. The LP activity and the inhibitory effect of activated LPs were evaluated by growing <span style="white-space:normal;"><i></span>E. coli<span style="white-space:normal;"></i></span> in pasteurized and boiled camel milk samples as contaminating agent. Results indicated that the <span style="white-space:normal;"><i></span>W. confusa<span style="white-space:normal;"></i></span> 22282 activated LPs generally showed significantly (P < 0.05) slower rates of acidification, lactic acid production and lower TBC and CC during the storage time compared to the non-activated sample. The H<sub>2</sub>O<sub>2</sub> producing LAB and exogenous H<sub>2</sub>O<sub>2</sub> activated LPs in pasteurized camel milk significantly reduced the growth of <span style="white-space:normal;"><i></span>E. coli<span style="white-space:normal;"></i></span> population compared to non-activated pasteurized milk. Overall, the result of acid production and microbial analysis indicated that the activation of LPs by H<sub>2</sub>O<sub>2</sub> producing LAB (i.e. <span style="white-space:normal;"> </span><span style="white-space:normal;"><i></span>W. confusa<span style="white-space:normal;"></i></span> 22282) maintained the storage stability of raw camel milk. Therefore, it can be concluded that the activation of LPs by biological method using H<sub>2</sub>O<sub>2</sub> producing LAB can substitute the chemical activation method of LPs in camel milk. 展开更多
关键词 Camel Milk Lactoperoxidase system Lactic Acid Bacteria preservation
下载PDF
Protective Effects of Different Hypothermal Preservation Solutions on Structure and Function of Isolated Rat Arteries
16
作者 Zhang-yong REN Shao-cheng LYU +4 位作者 Han-xuan WANG Jing WANG Lin ZHOU Qiang HE Ren LANG 《Current Medical Science》 SCIE CAS 2023年第4期768-778,共11页
Objective:With the increasing application of vascular reconstruction in surgical procedures,allogeneic vessels are becoming more popular in clinical practice due to their abundant sources,precise diameter matching,imp... Objective:With the increasing application of vascular reconstruction in surgical procedures,allogeneic vessels are becoming more popular in clinical practice due to their abundant sources,precise diameter matching,improved histocompatibility,and higher long-term patency rate.This study aimed to investigate the protective effect of various preservation solutions on the function and structure of the isolated rat abdominal aorta preserved under hypothermal conditions.Methods:The study utilized a total of 150 Sprague-Dawley(SD)rats,with 144 rats allocated to the experimental groups and 6 rats allocated to the control groups.The abdominal aorta of the rats was chosen as the subject of our research.The aorta in the experimental groups were randomly assigned to 4 groups:University of Wisconsin(UW)solution group,histidine-tryptophan-ketoglutarate(HTK)solution group,normal saline(NS)group,and sodium lactate Ringer's solution(RS)group.Samples were subjected to examination after preservation periods of 1 day,3 days,5 days,7 days,14 days,30 days,and 90 days.Evaluation of vascular physiological function involved detecting and assessing vasoconstriction ability and measuring cell viability through the MTT test.Evaluation of the vascular wall structure involved tension tolerance tests and pathological staining.Results:The pathogen-positive rate in the HTK group and NS group at 1 month was 16.7%.Regarding the vascular skeleton structure,both the UW group and HTK group exhibited intact structures after 2 weeks of preservation,with slightly edematous collagen and elastic fibers,which was significantly better than that of the NS group and RS group.In terms of cell activity and contractile function,all preservation groups showed similar effects within 2 weeks.However,after 2 weeks,the UW group showed the most favorable preservation effect(P<0.05).In terms of vascular tension,different groups exhibited similar effects within 1 week.However,after 2 weeks,the UW group showed the best preservation effect(P<0.05).Conclusion:All 4 types of preservation solution had a preservation effect on the structure and function of isolated blood vessels during short-term hypothermal preservation.However,after 2-week preservation,the UW solution was found to be the most suitable solution for the preservation of blood vessels. 展开更多
关键词 rat model allogeneic artery preservation solution vascular preservation technique vascular reconstruction
下载PDF
Exhumation and Preservation of the Jinchuan Ni-Cu-PGE Deposit under the East Longshou Mountain Thermal Evolution,Revealed by Apatite Fission Track Thermochronology
17
作者 LEI Xianghe YU Qiang +4 位作者 JIAO Jiangang LIU Jian SUN Xianyao HE Lijuan YANG Qike 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第2期486-500,共15页
Uplift and exhumation are important factors affecting the preservation of deposits.The anatomy of uplift-cooling evolution and exhumation in the East Longshou Mountain is of significant research value in understanding... Uplift and exhumation are important factors affecting the preservation of deposits.The anatomy of uplift-cooling evolution and exhumation in the East Longshou Mountain is of significant research value in understanding changes in the Jinchuan Ni-Cu-PGE deposit since its formation.This study uses apatite fission track(AFT)thermochronology to reconstruct the thermal history of the East Longshou Mountain,including the Jinchuan mine,revealing the uplift and exhumation history of the East Longshou Mountain and elucidating the preservation status of the Jinchuan deposit.The AFT ages in the East Longshou Mountain are distributed from 62.3±3.0 Ma to 214.7±14 Ma,with significant differences in ages in distinct areas,the central and pooled ages being consistent within the margin of error.Inverse thermal history models reveal two rapid cooling events associated with exhumation from the Early Jurassic to the Early Cretaceous(200–100 Ma)and since the Miocene(15–0 Ma),the former attributable to the far-afield response to the closure of the PaleoTethys Ocean and plate assembly at the southern margin of Eurasia,the latter associated with the initial India-Eurasia plate collision.A slow cooling event from the Early Cretaceous to the Miocene(100–15 Ma)is thought to be related to the arid environment in northwest China since the Cretaceous.These cooling events have diverse responses and cooling rates in different blocks of the East Longshou Mountain:the southwest and centre of which are mainly cooled over 200–120 Ma and 120–0 Ma,with cooling rates of~0.25 and~0.33°C/Ma(~1.25 and~0.33°C/Ma in the centre);the Jinchuan mine primarily cooled over 160–100 Ma,100–15 Ma and 15–0 Ma,with cooling rates of~1.33,~0.25 and~2.00°C/Ma.These differentiated coolings imply that the uplift of the East Longshou Mountain before the Miocene(~15 Ma)was integral.Strong uplift then occurred in the vicinity of the mining area,which is a critical period for the uplift of the Jinchuan deposit to the surface,meaning that the Jinchuan deposit was exposed no earlier than the Miocene(~15 Ma).Based on mineralization depth information obtained by previous researchers,in conjunction with the calculation and simulation results of this study,it can be seen that the bulk of the Jinchuan intrusion may still be preserved at depth. 展开更多
关键词 apatite fission track deposit preservation uplift-cooling Jinchuan Ni-Cu-PGE Deposit East Longshou Mountain
下载PDF
The Origin and Preservation of Suspended Barites near the 90°E Ridge in the Northeastern Indian Ocean
18
作者 BU Xuejiao LIU Ming +5 位作者 DING Yi YANG Yadi HUANG Mu SUN Xiaoxia FAN Dejiang YANG Zuosheng 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第1期88-98,共11页
Suspended particulate barite crystals were detected in the water columns at four different stations near the 90°E ridge in the Indian Ocean.Four distinct morphological types of marine barites were distinguished:e... Suspended particulate barite crystals were detected in the water columns at four different stations near the 90°E ridge in the Indian Ocean.Four distinct morphological types of marine barites were distinguished:euhedral-subhedral crystals,oval or round crystals,rhombic crystals,and irregular crystals.The barite crystals in the study area are typically fine,with a dominant size of 1–3μm.The vertical distribution of barites is significantly affected by the formation and sedimentation processes.Barites begin to appear at a depth of 30 m and are formed primarily from the surface to the depth of 2000m with a concentration peak at the depth of 200m,where particles are coarser than those in the other layers.The barites begin to settle and dissolve once formed in the water column,resulting in finer barite particles and lower particle concentrations.The formation of barite crystals is related to biological processes associated with the decomposition of barium-rich skeletons in the microenvironment of decaying organic matter that is affected by the primary productivity and dissolved oxygen content in the water column.The dissolving process of barite crystals showed similar variation with the concentration of dissolved barium in ocean water,and the substitution of strontium for barite in crystals promotes the selective dissolution of barite and exerts an important impact on its morphology.It is approximately 33%of barites in the amount and 22%in the concentration to settle to the bottom of the water column compared to that observed in the main barite formation zone. 展开更多
关键词 marine barite Indian Ocean origin and sedimentation process dissolution and preservation
下载PDF
Smart contract token-based privacy-preserving access control system for industrial Internet of Things
19
作者 Weizheng Wang Huakun Huang +3 位作者 Zhimeng Yin Thippa Reddy Gadekallu Mamoun Alazab Chunhua Su 《Digital Communications and Networks》 SCIE CSCD 2023年第2期337-346,共10页
Due to mobile Internet technology's rapid popularization,the Industrial Internet of Things(IIoT)can be seen everywhere in our daily lives.While IIoT brings us much convenience,a series of security and scalability ... Due to mobile Internet technology's rapid popularization,the Industrial Internet of Things(IIoT)can be seen everywhere in our daily lives.While IIoT brings us much convenience,a series of security and scalability issues related to permission operations rise to the surface during device communications.Hence,at present,a reliable and dynamic access control management system for IIoT is in urgent need.Up till now,numerous access control architectures have been proposed for IIoT.However,owing to centralized models and heterogeneous devices,security and scalability requirements still cannot be met.In this paper,we offer a smart contract token-based solution for decentralized access control in IIoT systems.Specifically,there are three smart contracts in our system,including the Token Issue Contract(TIC),User Register Contract(URC),and Manage Contract(MC).These three contracts collaboratively supervise and manage various events in IIoT environments.We also utilize the lightweight and post-quantum encryption algorithm-Nth-degree Truncated Polynomial Ring Units(NTRU)to preserve user privacy during the registration process.Subsequently,to evaluate our proposed architecture's performance,we build a prototype platform that connects to the local blockchain.Finally,experiment results show that our scheme has achieved secure and dynamic access control for the IIoT system compared with related research. 展开更多
关键词 Blockchain Privacy preservation Smart contract Industrial IoT
下载PDF
Asymmetric Consortium Blockchain and Homomorphically Polynomial-Based PIR for Secured Smart Parking Systems
20
作者 T.Haritha A.Anitha 《Computers, Materials & Continua》 SCIE EI 2023年第5期3923-3939,共17页
In crowded cities,searching for the availability of parking lots is a herculean task as it results in the wastage of drivers’time,increases air pollution,and traffic congestion.Smart parking systems facilitate the dr... In crowded cities,searching for the availability of parking lots is a herculean task as it results in the wastage of drivers’time,increases air pollution,and traffic congestion.Smart parking systems facilitate the drivers to determine the information about the parking lot in real time and book them depending on the requirement.But the existing smart parking systems necessitate the drivers to reveal their sensitive information that includes their mobile number,personal identity,and desired destination.This disclosure of sensitive information makes the existing centralized smart parking systems more vulnerable to service providers’security breaches,single points of failure,and bottlenecks.In this paper,an Improved Asymmetric Consortium Blockchain and Homomorphically Computing Univariate Polynomial-based private information retrieval(IACB-HCUPPIR)scheme is proposed to ensure parking lots’availability with transparency security in a privacy-preserving smart parking system.In specific,an improved Asymmetric Consortium Blockchain is used for achieving secure transactions between different parties interacting in the smart parking environment.It further adopted the method of Homomorphically Computing Univariate Polynomial-based private information retrieval(HCUPPIR)scheme for preserving the location privacy of drivers.The results of IACB-HCUPPIR confirmed better results in terms of minimized computation and communication overload with throughput,latency,and response time with maximized drivers’privacy preservation.Moreover,the proposed fully homomorphic algorithm(FHE)was compared against partial-homomorphic encryption(PHE)and technique without encryption and found that the proposed model has quick communication in allocating the parking slots starting with 24.3 s,whereas PHE starts allocating from 24.7 s and the technique without encryption starts at 27.4 s.Thus,we ensure the proposed model performs well in allocating parking slots with less time and high security with privacy preservation. 展开更多
关键词 Smart parking asymmetric consortium blockchain privacy preservation homomorphic encryption private information retrieval
下载PDF
上一页 1 2 54 下一页 到第
使用帮助 返回顶部